1. Field of the Invention
This invention relates to acoustic couplers and more particularly to universal, fluid insulated flexible acoustic muff systems.
2. Description of the Prior Art
An ordinary telephone can be used to connect a portable data terminal to a remote computer by lifting the telephone handset from its cradle and placing it on a handset-holding assembly of the data terminal. A microphone and speaker of the data terminal are then acoustically coupled to the earpiece and mouthpiece, respectively, of the handset. Although this type of acoustic coupling allows rapid connection to a telephone line, it can result in a high level of extra noise. The noise can arise from extraneous sounds and vibrations entering the microphone of the handset or terminal. One prior art design is the subject of U.S. Pat. No. 3,992,583, which is assigned to the assignee of this invention. Another design with primary emphasis on reducing external noise is described in U.S. Pat. No. 3,733,437, which describes an elastomeric coupling member having an inner wall for snugly receiving one end of the handset and an outer wall which concentrically surrounds the inner wall with a space provided between them. A thin annular membrane couples the upper ends of the inner and outer walls. The space between the inner and outer wall is maintained to prevent the inner wall from mechanical vibrations impressed on the outer wall.